20-10-2013, 02:08 PM
David, there might be an RF amp in his test receiver in the video, can't say for sure but I suspect there is, it's the regen detector that interests me, I think what the bloke is trying to do is design a regen detector where by the point of oscillation is kept constant across the band, so far as I can make out he's trying to do that by two seperate means, first by a hybrid feedback loop using an amalgamation of the Vackar and Armstrong topologies, then also by some sort of oscillator AGC loop to stabilize it further as well?
Somewhere I did see an earlier video where he was demonstrating the Vackar/Armstrong idea in practical terms over a wide frequency range and the results on his scope looked very good, constant amplitude of oscillation over a wide range has always been the holy grail for regens as most of us who have used or built regens will know. Interesting that the 6AS6 valve is also used in the Racal RA17 I seem to remember.
Lawrence.
Somewhere I did see an earlier video where he was demonstrating the Vackar/Armstrong idea in practical terms over a wide frequency range and the results on his scope looked very good, constant amplitude of oscillation over a wide range has always been the holy grail for regens as most of us who have used or built regens will know. Interesting that the 6AS6 valve is also used in the Racal RA17 I seem to remember.
Lawrence.
